Stripe Radar is a collection of tools to help businesses detect and prevent fraud. At Radar’s core is a machine learning engine that scans every card payment across Stripe’s 100,000+ businesses, aggregates information from those payments into behavioral signals that are predictive of fraud, and blocks payments that have a high probability of being fraudulent.

Radar’s power comes from all the data we obtain from the Stripe “network.” Instead of requiring users to label charges manually, Radar obtains the “ground truth” of fraud directly from our banking partners. Just as importantly, the signals we use in our models include aggregates over the entire stream of payments processed by Stripe: when a card is used for the first time on a Stripe business, there’s an 80% chance we’ve seen that card elsewhere on the Stripe network, and those previous interactions provide valuable information about potential fraud.

If you’re curious to learn more, we’ve put together a detailed outline that describes how we use machine learning at Stripe to detect and prevent fraud.